function getProvince() {
    var province = ["上海"];
    return province;
}

function getCityByProvince(province) {
    var arr = getProvinceAndCity();
    return arr[province];
}

function getProvinceAndCity() {
    var arr = {"上海": ["上海"]};
    return arr;
}

function getDistrictByCity(city) {
    var arr = getCityAndDistrict();
    return arr[city];
}

function getCityAndDistrict() {
    var arr = {"上海": ["黄浦区", "徐汇区", "长宁区", "静安区", "普陀区", "虹口区", "闸北区", "杨浦区", "闵行区", "宝山区", "青浦区", "松江区", "嘉定区", "奉贤区", "金山区", "浦东新区", "崇明县"]};
    return arr;
}
